Gte Laboratories Incorporated

Douglas D Tang

Robert J Regan

William C Rideout

A reconfigurable ring architecture for RF transport over fibers which eliminates the need for multiple pairs of fibers to serve multiple microcells and the need for backup communications lines as a result of system failure due to a fiber break. The ring architecture has a plurality of remote units which are interconnected to a host unit in a serial fashion. The host unit transmits signals to the plurality of remote units and receives signals from the plurality of remote units. Each of the remote units having photodetectors for receiving the transmitted signals and an antenna/transmitter for receiving other signals from another source; a splitter for splitting the transmitted signals into two parts, one part of the signals being output from the remote unit and the other part of the signals being transferred to adjacent remote units and then back to the host unit; and a transmitter for transferring the other signals from the remote unit to adjacent remote units and then back to the host unit. The transmission and reception of signals taking place even in the event of failure of a remote unit or the interconnection between remote units.

Reconfigurable ring system for the transport of RF signals over optical

A frequency hopping synthesizer is constructed from two FET-based multiplier circuits each responsive to a carrier input signal and a modulation signal to produce respective output signals which are in-phase combined to provide a frequency-shifted signal. The multiplier circuits each comprise two dual-gate field effect transistor (FET) amplifiers which are electrically balanced to suppress unmodulated carrier components so that only the modulated carrier signal appears. The respective carrier input signals and modulation signals are in quadrature phase relationship. A direct digital synthesizer controllably generates signal components which serve as the modulation signals for the multiplier circuits.

Frequency hopping synthesizer using dual gate amplifiers

A secure wireless party line system that can be used by a group of mobile users to communicate with each other like a wired party line but without the cumbersome inconvenience of long wired tether. The party line function is achieved by the use of a fixed wireless repeater. The fixed wireless repeater receives spread spectrum transmissions from all N mobile users at a frequency f1, and passes the received signals through an RF amplifier and upconverter, and then to an IF amplifier and power divider, which converts the received signals down to a convenient intermediate frequency (IF), and feeds N receive spread spectrum processors, each dedicated to receive a coded spread spectrum transmission from one user. The received voice outputs from the N users are then combined in a N-channel voice data multiplexer, and broadcast at a frequency f2 to all users with a common spread spectrum code word added by a transmit spread spectrum processor. The commonly coded broadcast messages are processed by an RF amplifier and broadcast at frequency f2. All mobile radio receivers receive on the same common code word used by the fixed wireless repeater for broadcasting. Each mobile user on said party line carries a simple single channel radio transceiver. Spread spectrum transmission provides security and anti-jamming performance. Analog and digital embodiments are disclosed.

Secure anti-jamming wireless party line

A base station in a cellular communications system is connected to a plurality of remote cellular sites by a communications link having a base terminal coupled to a remote terminal by two optical fibers. The base terminal receives RF downlink channels from the base station and optically transmits the RF channels as a non-overlapping composite signal to the remote terminal on a first fiber. The RF downlink channels are individually recovered at the remote terminal and distributed to disignated cell sites. The remote terminal also functions to receive RF uplink channels from the cell sites and optically transmit the RF channels as a non-overlapping composite signal to the base terminal on a second fiber. The RF uplink channels are indivicually recovered at the base terminal and forwarded to the base station.

Fiber optic antenna remoting for multi-sector cell sites

A method for generating a large number of stable microwave frequency components for wideband lightwave distribution networks is shown. A single oscillator is used at a transmitter to provide all of the required subcarriers. The subcarriers are modulated by high data rate channels and then multiplexed for transmission over a fiber optic line. At a receiver, all of the tuning frequencies required for channel selection are generated by a single oscillator.

Microwave subcarrier generation for fiber optic systems

An adjustable waveguide short circuit using a thin partition or rectangular pin parallel to the E-field in the waveguide and movable along longitudinal slots centrally located on the two broad walls of the waveguide.

Growing community of inventors

Chelmsford, MA, United States of America

Douglas D Tang